I am following this algorithm example: https://en.wikipedia.org/wiki/Christofides_algorithm#example
The graph:
Calculate minimum spanning tree T:
Calculate the set of vertices O with odd degree in T
Same as "the minimum spanning tree T" as the degree of all vertices are odd.
Form the subgraph of G using only the vertices of O
(as all were odd, this should give us the original graph)
Construct a minimum-weight perfect matching M in this subgraph
(I am not sure if I did this right)
Unite matching and spanning tree T ∪ M to form an Eulerian multigraph
This is definitely not right.